[libc++] Remove workarounds for missing __builtin_addressof

All supported compilers implement __builtin_addressof. Even MSVC implements addressof as a simple call to __builtin_addressof, so it would work if we were to port libc++ to that compiler. Differential Revision: https://reviews.llvm.org/D107905
llvm · Aug 11, 2021 · 7c81024 · 7c81024
1 parent 2c1789b
commit 7c81024
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Showing 9 changed files with 31 additions and 221 deletions.
diff --git a/libcxx/include/__config b/libcxx/include/__config
@@ -1283,10 +1283,6 @@ extern "C" _LIBCPP_FUNC_VIS void __sanitizer_annotate_contiguous_container(
 #  define _LIBCPP_SAFE_STATIC
 #endif
 
-#if !__has_builtin(__builtin_addressof) && _GNUC_VER < 700
-#define _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF
-#endif
-
 #if __has_attribute(diagnose_if) && !defined(_LIBCPP_DISABLE_ADDITIONAL_DIAGNOSTICS)
 #  define _LIBCPP_DIAGNOSE_WARNING(...) \
      __attribute__((diagnose_if(__VA_ARGS__, "warning")))

diff --git a/libcxx/include/__memory/addressof.h b/libcxx/include/__memory/addressof.h
@@ -21,8 +21,6 @@ _LIBCPP_PUSH_MACROS
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#ifndef _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF
-
 template <class _Tp>
 inline _LIBCPP_CONSTEXPR_AFTER_CXX14
 _LIBCPP_NO_CFI _LIBCPP_INLINE_VISIBILITY
@@ -32,19 +30,6 @@ addressof(_Tp& __x) _NOEXCEPT
     return __builtin_addressof(__x);
 }
 
-#else
-
-template <class _Tp>
-inline _LIBCPP_NO_CFI _LIBCPP_INLINE_VISIBILITY
-_Tp*
-addressof(_Tp& __x) _NOEXCEPT
-{
-  return reinterpret_cast<_Tp *>(
-      const_cast<char *>(&reinterpret_cast<const volatile char &>(__x)));
-}
-
-#endif // _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF
-
 #if defined(_LIBCPP_HAS_OBJC_ARC) && !defined(_LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF)
 // Objective-C++ Automatic Reference Counting uses qualified pointers
 // that require special addressof() signatures. When

diff --git a/libcxx/include/optional b/libcxx/include/optional
@@ -883,11 +883,7 @@ public:
     operator->() const
     {
         _LIBCPP_ASSERT(this->has_value(), "optional operator-> called on a disengaged value");
-#ifndef _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF
         return _VSTD::addressof(this->__get());
-#else
-        return __operator_arrow(__has_operator_addressof<value_type>{}, this->__get());
-#endif
     }
 
     _LIBCPP_INLINE_VISIBILITY
@@ -896,11 +892,7 @@ public:
     operator->()
     {
         _LIBCPP_ASSERT(this->has_value(), "optional operator-> called on a disengaged value");
-#ifndef _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF
         return _VSTD::addressof(this->__get());
-#else
-        return __operator_arrow(__has_operator_addressof<value_type>{}, this->__get());
-#endif
     }
 
     _LIBCPP_INLINE_VISIBILITY
@@ -1006,23 +998,6 @@ public:
     }
 
     using __base::reset;
-
-private:
-    template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR_AFTER_CXX17 _Up*
-    __operator_arrow(true_type, _Up& __x)
-    {
-        return _VSTD::addressof(__x);
-    }
-
-    template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-    static constexpr _Up*
-    __operator_arrow(false_type, _Up& __x)
-    {
-        return &__x;
-    }
 };
 
 #ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES

diff --git a/libcxx/include/type_traits b/libcxx/include/type_traits
@@ -4349,40 +4349,6 @@ inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
 typename __sfinae_underlying_type<_Tp>::__promoted_type
 __convert_to_integral(_Tp __val) { return __val; }
 
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-struct __has_operator_addressof_member_imp
-{
-    template <class _Up>
-        static auto __test(int)
-            -> typename __select_2nd<decltype(declval<_Up>().operator&()), true_type>::type;
-    template <class>
-        static auto __test(long) -> false_type;
-
-    static const bool value = decltype(__test<_Tp>(0))::value;
-};
-
-template <class _Tp>
-struct __has_operator_addressof_free_imp
-{
-    template <class _Up>
-        static auto __test(int)
-            -> typename __select_2nd<decltype(operator&(declval<_Up>())), true_type>::type;
-    template <class>
-        static auto __test(long) -> false_type;
-
-    static const bool value = decltype(__test<_Tp>(0))::value;
-};
-
-template <class _Tp>
-struct __has_operator_addressof
-    : public integral_constant<bool, __has_operator_addressof_member_imp<_Tp>::value
-                                  || __has_operator_addressof_free_imp<_Tp>::value>
-{};
-
-#endif // _LIBCPP_CXX03_LANG
-
 // is_scoped_enum [meta.unary.prop]
 
 #if _LIBCPP_STD_VER > 20

diff --git a/libcxx/include/version b/libcxx/include/version
@@ -199,9 +199,7 @@ __cpp_lib_void_t                                        201411L <type_traits>
 #endif
 
 #if _LIBCPP_STD_VER > 14
-# if !defined(_LIBCPP_HAS_NO_BUILTIN_ADDRESSOF)
-#   define __cpp_lib_addressof_constexpr                201603L
-# endif
+# define __cpp_lib_addressof_constexpr                  201603L
 # define __cpp_lib_allocator_traits_is_always_equal     201411L
 # define __cpp_lib_any                                  201606L
 # define __cpp_lib_apply                                201603L

diff --git a/...x/test/libcxx/utilities/meta/meta.unary/meta.unary.prop/__has_operator_addressof.pass.cpp b/...x/test/libcxx/utilities/meta/meta.unary/meta.unary.prop/__has_operator_addressof.pass.cpp
diff --git a/...x/test/std/language.support/support.limits/support.limits.general/memory.version.pass.cpp b/...x/test/std/language.support/support.limits/support.limits.general/memory.version.pass.cpp
@@ -178,17 +178,11 @@
 
 #elif TEST_STD_VER == 17
 
-# if TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700
-#   ifndef __cpp_lib_addressof_constexpr
-#     error "__cpp_lib_addressof_constexpr should be defined in c++17"
-#   endif
-#   if __cpp_lib_addressof_constexpr != 201603L
-#     error "__cpp_lib_addressof_constexpr should have the value 201603L in c++17"
-#   endif
-# else
-#   ifdef __cpp_lib_addressof_constexpr
-#     error "__cpp_lib_addressof_constexpr should not be defined when TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700 is not defined!"
-#   endif
+# ifndef __cpp_lib_addressof_constexpr
+#   error "__cpp_lib_addressof_constexpr should be defined in c++17"
+# endif
+# if __cpp_lib_addressof_constexpr != 201603L
+#   error "__cpp_lib_addressof_constexpr should have the value 201603L in c++17"
 # endif
 
 # ifndef __cpp_lib_allocator_traits_is_always_equal
@@ -274,17 +268,11 @@
 
 #elif TEST_STD_VER == 20
 
-# if TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700
-#   ifndef __cpp_lib_addressof_constexpr
-#     error "__cpp_lib_addressof_constexpr should be defined in c++20"
-#   endif
-#   if __cpp_lib_addressof_constexpr != 201603L
-#     error "__cpp_lib_addressof_constexpr should have the value 201603L in c++20"
-#   endif
-# else
-#   ifdef __cpp_lib_addressof_constexpr
-#     error "__cpp_lib_addressof_constexpr should not be defined when TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700 is not defined!"
-#   endif
+# ifndef __cpp_lib_addressof_constexpr
+#   error "__cpp_lib_addressof_constexpr should be defined in c++20"
+# endif
+# if __cpp_lib_addressof_constexpr != 201603L
+#   error "__cpp_lib_addressof_constexpr should have the value 201603L in c++20"
 # endif
 
 # ifndef __cpp_lib_allocator_traits_is_always_equal
@@ -424,17 +412,11 @@
 
 #elif TEST_STD_VER > 20
 
-# if TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700
-#   ifndef __cpp_lib_addressof_constexpr
-#     error "__cpp_lib_addressof_constexpr should be defined in c++2b"
-#   endif
-#   if __cpp_lib_addressof_constexpr != 201603L
-#     error "__cpp_lib_addressof_constexpr should have the value 201603L in c++2b"
-#   endif
-# else
-#   ifdef __cpp_lib_addressof_constexpr
-#     error "__cpp_lib_addressof_constexpr should not be defined when TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700 is not defined!"
-#   endif
+# ifndef __cpp_lib_addressof_constexpr
+#   error "__cpp_lib_addressof_constexpr should be defined in c++2b"
+# endif
+# if __cpp_lib_addressof_constexpr != 201603L
+#   error "__cpp_lib_addressof_constexpr should have the value 201603L in c++2b"
 # endif
 
 # ifndef __cpp_lib_allocator_traits_is_always_equal

diff --git a/.../test/std/language.support/support.limits/support.limits.general/version.version.pass.cpp b/.../test/std/language.support/support.limits/support.limits.general/version.version.pass.cpp
@@ -1285,17 +1285,11 @@
 
 #elif TEST_STD_VER == 17
 
-# if TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700
-#   ifndef __cpp_lib_addressof_constexpr
-#     error "__cpp_lib_addressof_constexpr should be defined in c++17"
-#   endif
-#   if __cpp_lib_addressof_constexpr != 201603L
-#     error "__cpp_lib_addressof_constexpr should have the value 201603L in c++17"
-#   endif
-# else
-#   ifdef __cpp_lib_addressof_constexpr
-#     error "__cpp_lib_addressof_constexpr should not be defined when TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700 is not defined!"
-#   endif
+# ifndef __cpp_lib_addressof_constexpr
+#   error "__cpp_lib_addressof_constexpr should be defined in c++17"
+# endif
+# if __cpp_lib_addressof_constexpr != 201603L
+#   error "__cpp_lib_addressof_constexpr should have the value 201603L in c++17"
 # endif
 
 # ifndef __cpp_lib_allocator_traits_is_always_equal
@@ -2091,17 +2085,11 @@
 
 #elif TEST_STD_VER == 20
 
-# if TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700
-#   ifndef __cpp_lib_addressof_constexpr
-#     error "__cpp_lib_addressof_constexpr should be defined in c++20"
-#   endif
-#   if __cpp_lib_addressof_constexpr != 201603L
-#     error "__cpp_lib_addressof_constexpr should have the value 201603L in c++20"
-#   endif
-# else
-#   ifdef __cpp_lib_addressof_constexpr
-#     error "__cpp_lib_addressof_constexpr should not be defined when TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700 is not defined!"
-#   endif
+# ifndef __cpp_lib_addressof_constexpr
+#   error "__cpp_lib_addressof_constexpr should be defined in c++20"
+# endif
+# if __cpp_lib_addressof_constexpr != 201603L
+#   error "__cpp_lib_addressof_constexpr should have the value 201603L in c++20"
 # endif
 
 # ifndef __cpp_lib_allocator_traits_is_always_equal
@@ -3254,17 +3242,11 @@
 
 #elif TEST_STD_VER > 20
 
-# if TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700
-#   ifndef __cpp_lib_addressof_constexpr
-#     error "__cpp_lib_addressof_constexpr should be defined in c++2b"
-#   endif
-#   if __cpp_lib_addressof_constexpr != 201603L
-#     error "__cpp_lib_addressof_constexpr should have the value 201603L in c++2b"
-#   endif
-# else
-#   ifdef __cpp_lib_addressof_constexpr
-#     error "__cpp_lib_addressof_constexpr should not be defined when TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700 is not defined!"
-#   endif
+# ifndef __cpp_lib_addressof_constexpr
+#   error "__cpp_lib_addressof_constexpr should be defined in c++2b"
+# endif
+# if __cpp_lib_addressof_constexpr != 201603L
+#   error "__cpp_lib_addressof_constexpr should have the value 201603L in c++2b"
 # endif
 
 # ifndef __cpp_lib_allocator_traits_is_always_equal

diff --git a/libcxx/utils/generate_feature_test_macro_components.py b/libcxx/utils/generate_feature_test_macro_components.py
@@ -66,8 +66,6 @@ def add_version_header(tc):
     "name": "__cpp_lib_addressof_constexpr",
     "values": { "c++17": 201603 },
     "headers": ["memory"],
-    "test_suite_guard": "TEST_HAS_BUILTIN(__builtin_addressof) || TEST_GCC_VER >= 700",
-    "libcxx_guard": "!defined(_LIBCPP_HAS_NO_BUILTIN_ADDRESSOF)",
   }, {
     "name": "__cpp_lib_allocator_traits_is_always_equal",
     "values": { "c++17": 201411 },